A claw of a transmission device designed as a hollow shaft is known from practice; through the axial adjusting movement, this is displaceable between a first end position, in which the claw is arranged rotatably in respect of a shaft of the transmission device, and a second end position, in which the claw is connected in a torque-proof manner to the shaft of the transmission device. If a shifting request, i.e., a transition movement of the claw between the first end position and the second end position, is calculated by an electronic transmission control unit, for example, due to increasing rotational speeds, in order to carry out the displacement movement of the claw, on the one hand, it is necessary to know the current position of the claw in an axial direction and the existing differential rotational speed between the shaft and the claw.
In order to determine the position of the claw in an axial direction, a known method is to design the claw with an encoder contour revolving on the circumference of the claw and to provide a sensor unit that interacts with the encoder contour. Thereby, one surface of the encoder contour is designed with a revolving v-shaped cross section. For the calculation of the axial position of the claw, the sensor unit features two measuring devices, in particular so-called “Hall cells,” spaced apart from each other in the axial direction of the component, and one permanent magnet arranged in respect of the claw on a side turned away from the measuring devices. By means of the measuring devices, a gap between an area of the sensor unit featuring the respective measuring device and the surface of the measuring signal reproducing the encoder contour can be calculated. A sensor signal formed through the difference of the two measuring signals is transformed into a useful signal by a filter device that eliminates interference; from the useful signal, the respective current axial position of the claw can be calculated.
With known transmission devices, the current rotational speed of a claw is calculated, for example, through a rotational speed sensor arranged on an additional component of the transmission device, whereas the rotational speed of the claw can be calculated through known fixed transmission ratio relationships from the rotational speeds measured by such rotational speed sensor. If it is not possible to calculate the rotational speed of the claw in such a manner, because, for example, there are undefined transmission ratio relationships, the rotational speed of the claw is to be calculated directly in the area of the claw. Accordingly, an additional encoder contour is provided in the area of the claw; this interacts with an additional sensor device. Through the provision of the additional encoder contour, the need for installation space for the claw in the axial direction of the claw is disadvantageously large.